In most cases you would want to heat your garden room in the winter months and also cool your working space in the summer months. Depending on your budget and expectations, options vary. It’s also worth noting how long it will be until you see a return on your investment. These will all influence your decision. 

Here are some useful options: - 

PV Solar Panels 

Photovoltaic (PV) conversion efficiency solar panels are several panels & likely need an inverter. Each panel can generate 200 - 350W of energy but in strong sunlight. The kits can cost around a £1,000.00 and depending on what you are powering the long-term cost will depend on how long the battery will last. Check what your power needs are before considering how many panels noting that winter darker months will impact performance naturally. There is a higher initial outlay, but you may need a secondary power source when the source is reduced. 

Electric Convector Heaters 

Typically, an electric convector heater will use around 2000W in power output which will make them expensive to run, if being used most days. These heaters can heat the air quickly (compared to oil & radiant heaters), so if you are using the room occasionally and just want it for short spurts, pound for pound these are a good option. 

Oil Filled Radiator 

Oil filled space heaters are 99% energy efficient, this means that all the electricity it uses is converted into heat. They are portable, so they can be placed where you need them. A 1500W heater at a higher hourly tariff rate will cost around £ 12.00 per week to run for £40.00 hours. 

 
Electric Radiators 

There are a large range of electric radiators on the market, we would put these in a similar bracket to the oil filled radiators, but the heat is more convective so if you are looking to spread the heat over a wider area, these might be a better option.

Wood burning stoves 

We highly recommend professional advice when considering this option as you will need to consider the roof and size of stove. You will need a professional installation and the correct airflow. So, if you have access to a ready supply of wood, this is a good option, but like other energy sources, if you need to buy the wood, consider if it’s worth the additional expense, albeit this is a very cosy option. 

Infra-red heating 

Like the oil filled radiators, if you have a small area that you want to heat this can be a way to cheaply and with little DIY add heating to your garden room. They are inexpensive to buy but don’t expect too much savings for efficiency compared to electric and oil filled radiators. 

Air to Air Heat pumps 

If you are looking for long term option and don’t mind the initial outlay, then Air to Air heat source pump could be a way forward, prices vary from £800 - £3,000 depending on the size of your space. This relatively modern energy efficient heat source uses heat from the sun and stored in the air. A 5kW pump can carry a A+++ rated for energy, so roughly this equates to around a £1.00 day to heat for 40 hours a month, depending on the set up, installation etc. This is a cost effective option but will need expert install and some maintenance. 

In summary, 

Work out your budget, how many hours and energy you need and then you can decide if it would be an expensive outlay for some of the more efficient heaters of if the money is better spent on better insulation and double glazing with a smaller less efficient heater. We can all agree that energy is not going to get any cheaper, so a long-term view needs to be approached.